There has been well known a sensor system which quantitates the concentration of a target substance contained in a sample by measuring electric current. In recent years, the sensor system described above has been widely applied to, for example, a biosensor system such as a small and easy type of blood sugar measuring system for quantitating the value of blood sugar contained in blood, or the like. Recently, the blood sugar measuring system, which is used for a blood sugar diagnosis or daily management of a diabetes patient, is commercially prevailed while being provided with many various functions. Recently, for example, the blood sugar measuring system is particularly of great importance in the field of a data management such as a management or processing of measured data.
In general, measurement accuracy of the biosensor system including a sensor and a measuring device is periodically managed using, for example, an exclusive standard fluid (referred to “control fluid” hereinafter), in order to maintain or manage the measuring accuracy. As the control fluid, there may been used a solution in which a known amount of glucose is dissolved in pure water, the solution being colored with a pigment in accordance with its use, or being provided with a hydrophilic polymer so as to adjust its viscosity.
In the conventional biosensor system in which its measurement accuracy is managed using the control fluid, it is required that the measured data of the control fluid is not confusedly processed as the measured data of the body fluid or the like used as an ordinary sample. Accordingly, before the control fluid is introduced into the biosensor system, the measuring mode is changed to that for the control fluid by a predetermined manual operation of the measuring device so as to distinguish its measuring data from the measuring data of the body fluid or the like.
However, in the conventional biosensor system described above, when the control fluid is introduced, it is required to change the measuring mode by the manual operation for changing the mode, for example, button operation or the like. In consequence, there is such a problem that the measured data for the control fluid may be managed while erroneously being recognized as the measured data for the body fluid or the like by erroneously performing or forgetting the operation. Meanwhile, there may be also such a problem that the operation for manually changing the mode is troublesome. In particular, for a diabetes patient or the like having trouble in the eyes or fingertips, it may be difficult to change the mode by the manual operation. Therefore, there is requested a biosensor system, which can automatically discriminate whether a sample introduced into the biosensor system is a body fluid or a control fluid.